Transportation sustainability is of increasing concern to professionals and the public. This paper describes the modeling and calculation of sustainability performance measures in a transportation data archive. The purpose of these measures is to assess the sustainability of the Portland, Oregon, metropolitan freeway system. The measures were developed to be part of, and to use the data from, the Portland Oregon Regional Transportation Archive Listing (PORTAL) at Portland State University. These performance measures estimate vehicle emissions (carbon monoxide, volatile organic compounds, nitrogen oxides, and carbon dioxide), fuel consumption, cost of time delay, and person mobility (travel in person hours and person miles and delay in person hours). Methods for modeling and necessary data are described. Future plans call for integrating these measures into the PORTAL web interface to expand the types of performance measures used for regional transportation planning and operations.